Infratentorial neurosurgery is an independent risk factor for respiratory failure and death following intracranial tumor resection

Transcription

1 --- Supplemental Digital Content--- Infratentorial neurosurgery is an independent risk factor for respiratory failure and death following intracranial tumor resection Alana M. Flexman Bradley Merriman Donald E. Griesdale Kelly Mayson Peter T. Choi Christopher J. Ryerson 20

2 Supplemental Table 1. Common Procedural Terminology (CPT) Codes used for analysis. CPT CODE DESCRIPTION NUMBER OF CASES SUPRATENTORIAL Craniectomy, trephination, bone flap craniotomy; for excision of brain tumor, supratentorial, except meningioma Craniectomy, trephination, bone flap craniotomy; for excision of meningioma, supratentorial Craniectomy, bone flap craniotomy, transtemporal (mastoid ) for excision of cerebellopontine angle tumor INFRATENTORIAL Craniectomy for excision of brain tumor, infratentorial or posterior fossa; except meningioma,cerebellopontine angle tumor, or midline tumor at base of skull Craniectomy for excision of brain tumor, infratentorial or posterior fossa; meningioma Craniectomy for excision of brain tumor, infratentorial or posterior fossa; cerebellopontine angle tumor Craniectomy for excision of brain tumor, infratentorial or posterior fossa; midline tumor at base of skull

3 Supplemental Table 2. Variable definitions for exclusion criteria as described in the National Surgical Quality Improvement Program database. VARIABLE LABEL VARIABLE OPTIONS AT ENTRY ANESTHES Principal anesthesia technique Epidural General Local Monitored Anesthesia care None Other Regional Spinal Unknown VENTILAT Ventilator dependent Yes; No; Unknown ASACLAS ASA classification 1-No Disturb; 2-Mild Disturb; 3- Severe Disturb; 4-Life Threat; 5- Moribound COMA Coma > 24 hours Yes; No; Unknown QUAD Quadriplegia Yes; No; Unknown PREGNANCY Pregnancy Yes; No; Unknown 22

4 Supplemental Table 3. Primary outcome variables used for composite outcome of respiratory failure and death as described in the National Surgical Quality Improvement Program database. VARIABLE LABEL DEFINITION DREINTUB FAILWEAN DOPERTOD Occurrences Unplanned Intubation Occurrences Ventilator > 48Hours Days from operation to death Patient required placement of an endotracheal tube and mechanical or assisted ventilation because of the onset of respiratory or cardiac failure manifested by severe respiratory distress, hypoxia, hypercarbia, or respiratory acidosis within 30 days of the operation. In patients who were intubated for their surgery, unplanned intubation occurs after they have been extubated after surgery. In patients who were not intubated during surgery, intubation at any time after their surgery is considered unplanned. Total duration of ventilator-assisted respirations during postoperative hospitalization was greater than 48 hours. This can occur at any time during the 30-day period postoperatively. This time assessment is CUMULATIVE, not necessarily consecutive. Ventilator-assisted respirations can be via endotracheal tube, nasotracheal tube, or tracheostomy tube. We included only those who failed to wean within 48 hours immediately following intubation for their surgical procedure. Patients who failed to wean from ventilation following a re- intubation were not captured under this definition, but rather as an unplanned intubation. Days from operation to death. Death was calculated from the number of data points collected under this variable as there is no standalone variable for death. 23

5 Supplemental Table 4. Variable definitions for predictor variables. VARIABLE NAME VARIABLE LABEL VARIABLE OPTIONS AT ENTRY SEX Gender Male; Female AGE Age of patients Age of patient with patients over 89 coded as 90+ HEIGHT WEIGHT Height Weight SMOKE Current smoker within 1 year Yes; No; Unknown PACKS ETOH Pack-years of smoking EtOH > 2 drinks/day in 2 wks before admission Yes; No; Unknown DYSPNEA Dyspnea At rest; moderate exertion; no; unknown FNSTATUS2 Functional health status Prior to Surgery HXCOPD History of severe COPD Yes; No; Unknown CPNEUMON Current Pneumonia Yes; No; Unknown IMPSENS Impaired Sensorium Yes; No; Unknown PRBUN PRALBUM Preoperative BUN Pre-operative serum albumin EMERGNCY Emergency case Yes; No; Unknown ANETIME Duration of Anesthesia Independent; Partially Dependent; Totally Dependent; Unknown In older databases, FNSTATUS1 may have been used instead, with same options Patients were considered to have Cardiac Disease if they had any of the following positive variables: HXCHF Congestive heart failure (CHF) in 30 days before surgery HXMI History of myocardial infarction 6 mos prior to surgery Yes; No; Unknown Yes; No; Unknown PRVPCI Previous PCI Yes; No; Unknown PRVPCS Previous cardiac surgery. Yes; No; Unknown HXANGINA History of angina in 1 month before surgery Yes; No; Unknown Patients were considered to have Neurologic Disease if they had any of the following positive variables: HEMI Hemiplegia Yes; No; Unknown CVA CVA/Stroke with neurological deficit Yes; No; Unknown PARA Paraplegia Yes; No; Unknown 24

6 Supplemental Table 5. Steps in development of the final multivariate model. MODEL VARIABLES* CHANGE N 1 Age, functional status (tri), COPD, emergency surgery, BUN, albumin 2 Model 1 + surgical site, dyspnea (tri), cardiac disease, impaired sensorium, neurological disease, anesthetic duration Base model from Arozullah et al Add predictors with bivariate p < Model 2 BUN, albumin Remove variables not independently associated with PRF 4 Model 3 COPD Compare COPD and dyspnea variables 5 Model 4 Functional status Compare neurological disease, impaired sensorium and functional status variables AURO C GOF * Functional status is a 3-level variable (totally dependent, partially dependent, independent); dyspnea is a 3-level variable (dyspnea at rest, dyspnea with moderate exertion, no dyspnea) Abbreviations: AUROC, area under the receiver operating characteristic curve; BUN, blood urea nitrogen; COPD, chronic obstructive pulmonary disease; GOF, goodness of fit (Hosmer- Lemeshow). 25

7 Supplemental Figure 1. Patient selection. *Data from 2006 includes patients undergoing surgery in 2005; none of these patients had a neurosurgical procedure. 26

8 Supplemental Figure 2. Adjusted risk of postoperative respiratory failure and death (composite outcome) for age and anesthetic duration, stratified by surgical location. Shaded areas represent 95% confidence intervals. Composite outcome, % Age (years) Composite outcome, % Anesthetic duration (hours) Infratentorial Supratentorial 27